Virtual machines running in a cloud are not well protected from other machines in the cloud, or from devices with physical access to the cloud. For example, virtual machines executing in a cloud may receive communications from any device in the cloud. Further, data transmitted by the virtual machine in the cloud may be intercepted by unintended recipients.
In a conventional solution, a network may include a plurality of servers hosting virtual machines leased by tenants. The virtual machines may start and stop based on demand for the tenant's services. Because the virtual machines are frequently starting and stopping there are no dedicated resources for the tenant. This reduces the cost for the tenant, because resources are only used when they are needed. Thus, the tenant only pays for resources as they are used. However, because there is no leased hardware for the tenant, the tenant's virtual machines may start on any one of a number of server systems in the network.
For example, a tenant may be a customer owning one or more virtual machines executing within the network. Because the virtual machines execute on shared hardware with other virtual machines belonging to other tenants, the transmission to and/or from the virtual machine may be intercepted by another tenant. Conventional solutions for isolating hardware of one tenant from hardware of another tenant are not useful for improving security, because any tenant's virtual machine may execute on hardware with another tenant's virtual machines.